Tonoscope



Sept; 1942- -c. F. E-LTON: 2,296,7.7 7

TONOSCOPE Filed Dec. 4, 1959 2 Sheets Sheet l AMPLIFIER 85 AMP.

Sept. 22, 1942. ELTON I 2,296,777

TONOSCOPE Filed Deb. 4, 1939 2 Sheets-Sheet 2 Patented Sept. 22, 1942UNITED STATES PATENT OFFICE TONOSCOPE Carey F. Elton, Gadsden, Ala.

Application December 4, 1939, Serial No. 307,484 8 Claims. (or. 88-14)My invention relates to tonoscopes or stroboscopic tuning devices andhas as one of the principal objects thereof the provision of truestandards of musical pitch relations in a device of the above describedcharacter, with means for indicating the similarity, relative to thetrue diatonic musical scale and correlative semitones thereof, ofmusical tones when sung, played on an instrument, through radio or fromany sound source.

Another object of this invention is the provision of a graphic plan ofthe order of harmony, the chords of the scale, the frequency relationsof the various tones of the musical scale and combinations thereof inthe stroboscope design for simple demonstration of the basic principlesof harmony.

Another object is the provision of a simple and practical standard ofthe Equal Temperament musical scale to facilitate setting thetemperament of pianos, organs or other tempered instruments, and fortuning any number or kind of musical instruments to any desired pitchwithin their range; extremely low frequencies of pipes or strings,however indefinite to the sense of hearing, being easily indicated withprecision with this device.

A further object of this invention is the provision of means forutilizing the sixty cycle frequency of ordinary lighting circuits as astandard for establishing a stroboscope frequency indicative ofinternationa1 pitch (A440) by means of proportional frequencies; theseveral fixed ratios of frequencies on one stroboscope eliminating anypossibility of variation between them.

A special object of my invention is the provision of a device of theabove described character which is simple in construction, effici-ent inoperation and economical in manufacture.

Other objects and advantages will appear in the following description,the appended claims and the annexed drawings.

In the drawings:

Figure 1 is a front elevation of my invention, less controls.

Figure 2 is a side elevation thereof, less controls and with amplifierremoved.

Figure 3 is a front elevation in partial section on an enlarged scaleshowing the position of illuminators within the cylindrical stroboscope.

Figure 4 is a diagram of the electrical circuits employed in operatingmy device.

Figure 5 is a top plan View of my novel arrangement of frequencypatterns for a music stroboscope in disk form, this form beinggraphically illustrative of harmony and pitch rela-- tions.

Figure 6 is a perspective View illustrating a modified form of myinvention in which the stroboscope in disk form reflects the soundmodified illumination.

In practicing my invention as illustrated in Figures 1 to 4 inclusive ofthe drawings, I employ a cabinet equipped with observation windows 66.Securely attached to the base 61 of the cabinet is a motor support 68which extends vertically to the top of the cabinet where it is furthersecured and on which is mounted a motor 70, the latter having connectedthereto a speed governor 'H for governing the speed thereof.

The governor control is a brake lever 12 which is mounted in a bearing73 which is formed in a part of the motor housing. The opposite end ofbrake lever 12 is provided with a brake 14, the latter being adjustablein its engagement with the governor brake plate 75 by means of speedadjusting screw 16 disposed in engagement with brake lever 12 and actingagainst spring 11. The adjusting screw 16 is threaded in a bearing 18formed in a part of the motor housing, the outer end of said screw beingprovided with a finger-piece 79 whereby upon manual adjustment of thespeed adjusting screw 16 the brake lever 72 is actuated to effectadjustment of the governor H and thus vary the speed of the motor asdesired.

The motorlfl is connected by means of wiring 80 to the plug receptacle8| which has terminals for connection to a source of electrical energy(not shown), the latter being of the 60 cycle 110 volt type ofalternating current.

One of the wires 80 between the motor 10 and the receptacle 8| to whichit is connected, has interposed therein a manually operated switch 82,the latter being mounted in the top of the cabinet. The wires 83 fromthe receptacle 8| connect the amplifier into the'llO volt A. C. circuit,the amplifier switch 84 being in said circuit.

The amplifier 85 is of ordinary construction, such as is used in radiosor small public address systems, the output terminals 89 of which areconnected to neon lamps 9B in this device instead of the usualloudspeaker. Said amplifier is connected to microphone 86 by means ofwires 81 whereby sound vibrations picked up by said microphone aretransmitted to the amplifier 85 for amplification and translation,through the medium of the neon lamps 90 into corresponding lightfiuctuations, the purpose of all of which is hereinafter set forth.

Mounted on the shaft of the motor 19 is a rotary member 88 in the formof a hollow cylinder having one open end, the closed end being securedto the motor shaft. The curved wall of said cylinder is formed oftransparent material, the open end of the cylinder being maintained intrue form by an annular rib 9i. Mounted upon a bracket 92 which extendswithin the open end of the transparent cylinder 89 are the neon lamps 99referred to above. Said lamps are connected to amplifier outputterminals as described and as illustrated in the drawings Figures 3 and4.

In Figure 3, the stroboscope frequency patterns in zones 49 to 54 areprinted in opaque ink on translucent paper, said paper being placed onthe transparent cylindrical wall of the rotary member 88 in the mannerof a closely fitting band about said wall, said frequency patterns beingin the form of parallel, vertical, circular zones.

Zone 49 has divisions of distinctive design and is used only forestablishing pitch at A440. Zones 59 to 62 are the musical scaleindicators arranged to resemble a piano keyboard; the zones of thenatural tones being distinguished by translucence, the sharps byopacity. The frequency patterns of zones 63 and 94 have divisions ofanother distinctive design and are used only for setting the temperamentof tempered musical instruments.

The sixty cycle content of the amplifier output (called A, C. hum andprevalent in all amplifiers of this type), is regulated by the volumecontrol 93 on top of the cabinet. The said sixty cycle frequency willilluminate the stroboscope one hundred and twenty times per second. Zone59 is divided into forty-eight equal parts. With the speed of thestroboscope adjusted to two and one half revolutions per second, thesaid adjustment being indicated by synchronism of zone 59 with the saidsixty cycle illuminations at the rate of 120 per second, each of thesaid divisions of zone 59 will be successively illuminated in the exactposition of its antecedent division, the entire zone thus appearingmotionless.

With zone 59 synchronized with the sixty cycle illumination, theeighty-eight square-shaped divisions of zone 49 will also be moving atthe rate of two and one half R. P. S., or 220 divisions per secondrelative to a given point, and the sound of A at 220 vibrations persecond, picked up by microphone 86 and amplified to sufficient voltageto flash the lamps 99, will cause the zone 49 to appear stationary thusindicating syncronism of the sound with the standard. A sound of 221 V.P. S. would cause apparent recession of the zone at the rate of onedivision per second, Or 219 V. P. S. would cause apparent procession atthe same rate.

Only similarity (perfect r partial resemblance), of the sound to thestandard is indicated. Extent and manner of variation are indicated byrate and direction of apparent motion; the standard tone being nototherwise indicated except when sounded, in which case it is indicatedby apparent stability of the zone.

With the stroboscope speed maintained by the governor H at two and onehalf R. P. S. as indicated b synchronismof zone 50 with the 60 cyclefrequency, the sound of A at 110 V. P. S. would cause illumination ofzone 49 only 44 times during its cycle, or the A at 55 V. P. S.

would successively illuminate each of the 88 divisions of the zone inthe exact position of its fourth antecedent, or only 22 times during itscycle, thus all of the lower As at this speed would exhibit the actualnumber of divisions, differing only in brilliancy. A-440 (theinternational standard of pitch) would illuminate the 88 divisions ofzone 49 at 176 equally spaced points in the cycle thus causing the zoneto appear as having 176 divisions instead of the actual 88. By doublingthe speed of the stroboscope to 5 R. P. S. the sound of A-440 wouldcause zone 49 to appear motionless in its actual design.

To set the temperament of a piano, the A unisons and octaves would betuned to zone 49 in the manner described. From this point the procedurewould be the synchronization of zone 64 with the frequency of the lastnote tuned and then tuning the next lower semitone and its octaves tosynchronism with zone 63 and so on down the scale, or reversely up thescale.

If the piano were tuned to the true musical scale it would be in perfecttune in one key and unequally out of tune in all other keys; whereas inthe tempered scale no two of its tones are in tune in any key but allare more or less equally out of tune in all keys; the total variationsof the true scale in the twelve keys being approximately one thirdgreater than those of the tempered scale.

With the pitch of some instrument tuned to A440 and zone 59 (the la or Azone) tuned to A of said instrument, the zones 50 to 62, Figure 3, wouldbe indicative of the tones of the true scale in the key of C, thekeynote being indicated by zone 59. To practice singing or playing indifferent keys zone 50 is synchronized with the sound of the desiredkeynote, thus moving the entire ratio up or down as the case might be;the true scale being always indicated as in the key of C regardless ofits actual pitch. When used as a tempered scale (changing keys withoutspeed adjustment), the maximum deviation from true pitch isapproximately one third greater than the maximum deviation of thetempered scale.

The ratio of the semitonic intervals of the true musical scale hereinreferred to was derived from the fact that three successive groups ofintervals comprising the known and established diatonic scale are the3rd, 4th and 5th harmonics of common successive fundamentals. Withfundamentals regarded as 1st harmonics and the ratio of do, re, mi,being established at 8, 9, 10, the relation of the three parts of thetrue diatonic scale is as follows:

Fundamen 2nd 3rd 4th 5th 6th talor harmonic harmonic harmonic harmonicharmonic harmonic 32fa 40la.. 48do.

36 so 45 ti order with the harmonic regarded as the multiple:

In the following numerical ratios the correlation of the diatonic andsemitonic musical scales is evident:

Frequency 48 51 54 57 60 64 68 72 76 80 85 90 Established scale ratio15-16 8- 9 Diatonic l 8- 9-l0 8 9-l0 15 New l6l7l81920 16l7181920 30Scmitonic scale ratio l. 15--16 16-17-18 In Figure the complete cycle ofthe above musical scale frequencies is arranged in a form graphicallyillustrative of all of the frequency relations. It may be noted that allof the scale zones are in phase at 48. Beginning at this point, theorder of the relation (harmony), of the several zones is indicated bythe order of the synchronism of their respective divisions with those oftheir keynote zone 59, the said keynote divisions coinciding as follows:1, 2, 3, 4, with the octave, 5th, 4th and 3rd intervals. 8, with the 2ndand 7th, 12, with the 135th and Dfith, IS, with DZnd and D3rd, and 8,with D7th.

Although the note of the diminished 7th is least related to its keynoteand only half as harmonious in this relation as the established 2nd and7th chords of the scale, the frequence of its synchronism with othernotes is comparable with other notes in such relation. It may be alsonoted that the semitonic relations of the herein described chromaticmusical scale are exactly one half as harmonious as the establisheddiatonic relations, the-latter being in total synchronism on the 24thand the former on the 48th vibration of their keynote.

A modified form of my invention is illustrated in Figure 6, wherein thestroboscope illustrated in Figure 5 in the form of a disk is placed onthe rotating member 88 and rotated by a governor-controlled motor Withinthe cabinet 65, its speed being adjustable by means of the governoradjusting screw 79 for synchronizing any desired zone of the stroboscopewith the frequency of fluctuations of the lamp 9%, the said fluctuationsbeing effected by means of the amplifier 85 and microphone 86, saidmeans being actuated by vibrations of a sound source, the indicativemeans of the zones coacting with said lamp during fluctuations thereoffor indicating similarity of sounded tones to the standards establishedby the several zones on the stroboscope.

It is obvious that the herein described chromatic musical scale and thisinvention in which it is used are not confined to the uses hereindescribed, as either may be utilized for any purpose for which it isadaptable. It is also to be understood that the invention is not limitedto the specific construction as illustrated and described, as the sameis only illustrative of the principles of its operation which arecapable of extended application in advance forms, and that the inventioncomprehends all construction within the scope of the appended claims.

What I claim is:

1. In a tonoscope, a light, means to fluctuate the light responsive tothe known constant frequency of an alternating electric current, othermeans to fluctuate said light responsive to sound Waves, a rotary memberilluminated by the fluctuations of said light, means to vary the speedof said rotary member, a series of stroboscopic indicia on the rotarymember adapted when said member is rotating at a predetermined speed andis illuminated by said light fluctuating at said known constantfrequency to appear motionless, and other series of stroboscopic indiciaon the rotating member related to each other as are the tones of themusical scale whereby when said member is rotating at said predeterminedspeed and is illuminated by said light fluctuating responsive toselected sound waves said other series of indicia appear motionless whensaid sound waves fluctuate at frequencies corresponding thereto andindicate visually the relationship of the musical tones embodied in saidsound waves.

2. In a tonoscope, a light, means to fluctuate the light at the knownconstant frequency of an alternating electric current, other means tofluctuate said light responsive tothe frequency of sound waves, arotating member illuminated by the fluctuations of said light, means toadjust the speed of said member, a series of stroboscopic indicia on therotary member adapted when said member is rotating at a predeterminedspeed and is illuminated at said known frequency to appear stationary,another series of stroboscopic indicia on the rotating member adaptedwhen said member is rotating at said predetermined speed and isilluminated responsive to a selected keynote of the musical scale toappear stationary, and a plurality of other series of stroboscopicindicia on the rotary member interrelated in accordance with the notesof the musical scale, whereby when said member is rotating at saidpredetermined speed and is illuminated by said light fluctuatingresponsive to other selected sound waves, said other series of indiciaindicate visually the relationship of the notes of the musical scaleembodied in said sound waves.

3. A tonoscope comprising a light, means to fluctuate the said lightresponsive to sound waves, a member mounted for rotation in position tobe illuminated by the fluctuations of said light, means for rotatingsaid member at a con stant speed, zones of stroboscopic indicia on therotating member differing in number in accordance with the frequencyratio of the notes of the chromatic musical scale and adapted whenilluminated responsive to selected sounds and when the light isfluctuating in synchronism with said zones to appear stationary and thusindicate graphically the conformity of said selected sounds with thefrequency ratio of the notes of the chromatic musical scale, and meansto adjust the speed of said member to cause any of said zonesselectively to synchronize with the fluctuations of said lightresponsive to a selected musical note.

4. A tonoscope comprising a light, means to fluctuate the lightresponsive to the vibrations of sound waves, a rotary stroboscopicmember adapted to be illuminated by the light, means to rotate saidstroboscopic member, a plurality of series of indicia on thestroboscopic member, the indicia of the individual series differing innumber as do the vibrations of the notes of the musical scale, and meansto adjust the speed of said stroboscopic member to cause the separateseries thereof to appear stationary responsive to the sounding ofmusical notes so related to each other in vibrations.

5. A tonoscope comprising a light, means to fluctuate the light at theknown constant frequency of an alternating electric current, other meansto fluctuate the light responsive tothe vibrations of sound waves, arotary stroboscopic member adapted to be illuminated by the light, meansto adjust the speed of the stroboscopic member, a series of stroboscopicindicia on the member adapted to appear stationary when illuminatedresponsive to the fluctuations of the alternating current and when thespeed of the rotary member has been adjusted to a predetermined value,said series also being adapted to appear stationary when rotating atsaid speed and when illuminated by the light fluctuating responsive to aselected keynote of the musical scale having a frequency which is amultiple of the fluctuations at said known frequency of said light, andother series of stroboscopic indicia on the member related in number tothe first mentioned series as are the corresponding notes of the musicalscale to the keynote, and each adapted to appear stationary when saidmember is rotating at said constant speed and is illuminated responsiveto one of said musical notes.

6. A tonoscope comprising a light, means to fluctuate the light at theknown constant frequency of an alternating electric current, other meansto fluctuate the light responsive to the virations of sound waves, arotary stroboscopic member adapted to be illuminated by the light, meansto adjust the speed of the stroboscopic member, a series of stroboscopicindicia on the rotary member adapted to appear stationary whenilluminated responsive to the fluctuations of the alternating currentand when the speed of the rotary member has been adjusted to apredetermined value, said series of indicia also being adapted to appearstationary when rotating at said speed and when illuminated by saidlight fluctuating responsive to a selected keynote of the musical scalehaving a, frequency which is a multiple of the fluctuations at saidknown frequency of said light, and other series of stroboscopic indiciaon the rotary member related in number to the first mentioned series asare the corresponding notes of the diatonic musical scale and thecorrelated semitones thereof to the keynote, and each adapted to appearstationary when said rotary member is rotating at said constant speedand is illuminated responsive to one of said musical notes, and a pairof series of indicia side by side on said stroboscopic member related toeach other in number as are the semitones of the tempered musical scale,each of said series being adapted to appear stationary when illuminatedby a light fluctuating at the frequency of a selected musical note andwhen the speed of said stroboscopic member is adjusted for said seriesto synchronize with the fluctuations of the light.

'7. A tonoscope comprising a light, means to fluctuate the light at apredetermined frequency which is a multiple of the frequency of amusical tone at standard pitch, other means to fluctuate the lightresponsive to sound waves, a rotating member in position to beilluminated by the fluctuations of said light and having thereon aplurality of series of stroboscopic indicia which are related to eachother in number as are the frequencies of the notes of the true musicalscale and its correlated semitones, other series of stroboscopic indiciaon the rotating member which bear the same relation to each other innumber as do the proximate semitones of the tempered musical scale, saidother series being adapted when illuminated responsive to selected soundwaves to indicate visually the conformity of said selected sound waveswith standard tempered proximate semitones, and means to adjust thespeed of the rotating member to synchronize the stroboscopic indiciathereon with the fluctuations of the light.

8. A device for tuning musical instruments in accordance with the truemusical scale and the tempered scale selectively, comprising a light,means to fluctuate the light at a frequency of fluctuations per second,other means to fluctuate the light responsive to sound waves, a rotatingmember in position to be illuminated by the fluctuations of said light,a series of stroboscopic indicia on said member adapted to appearstationary when illuminated at a frequency of 120 fluctuations persecond and when said member is rotating at a predetermined speed, asecond series of indicia on said rotating member which in number areequal to a multiple of 440 and adapted to appear motionless whenilluminated responsive to a sound wave of A at international pitch andwhen said member is rotating at said predetermined speed, other seriesof stroboscopic indicia on the rotating member the individual patternsof which are so related to each other as to be graphicallyrepresentative of the pure musical scale including the correlatedsemitones thereof and adapted when illuminated by the light fluctuatingresponsive to corresponding musical notes to appear motionless andvisually indicate the relationship of said notes, and still other seriesof indicia on said rotating member the individual patterns of which arerelated to each other as are the proximate semitones of the temperedmusical scale and adapted to appear motionless when illuminated by thelight fluctuating responsive to sounds corresponding to proximatesemitones of the tempered musical scale, and means to adjust the speedof the rotating member to synchronize the stroboscopic indicia thereonwith the fluctuations of the light.

CAREY F. ELTON.

